replacementn.
英 rɪ'pleɪsm(ə)nt | 美 rɪ'plesmənt
中文n. 更换；复位；代替者；补充兵员
词根词源
replacement (n.)"act or fact of being replaced," 1790, from replace (v.) + -ment. Meaning "something that replaces another" is attested from 1894.
关键词